Sheet feeding device, image forming device, and method for feeding sheets

An image forming apparatus comprising:

• an image forming section configured to form an image on a sheet;
• and
• a sheet feeding section comprising:
• a first storing unit configured to store sheets therein;
• a second storing unit configured to store sheets therein and disposed farther from an image forming section than the first storing unit;
• a first feeding unit configured to feed sheets from the first storing unit to the image forming section;
• a second feeding unit configured to feed sheets from the second storing unit to the image forming section;
• and
• a control unit configured to
• determine a total number of sheets to be printed, a storing unit as designated by a user, and a storing unit that stores sheets of same size and type as sheets stored in the designated storing unit and is disposed farther from the image forming section than the designated storing unit, as a subsequent storing unit, and
• control the feeding units to feed a first sheet from the first storing unit if the first storing unit is determined as the designated storing unit,
• if the total number exceeds a threshold number and the second storing unit is determined as the subsequent storing unit, then to start feeding a second sheet from the second storing unit while the first sheet is being conveyed from the first storing unit, and
• if the total number does not exceed the threshold number, or if no storing unit is determined as the subsequent storing unit, then to feed a second sheet from the first storing unit.

A method for feeding sheets from a sheet feeding device to an image forming section of an image forming apparatus, the sheet feeding device including a first storing unit configured to store sheets therein and a second storing unit configured to store sheets therein and disposed farther from an image forming section than the first storing unit, the method comprising:

• determining a total number of sheets to be printed;
• determining a storing unit as designated by a user;
• determining a storing unit that stores sheets of same size and type as sheets stored in the designated storing unit and disposed farther from the image forming section than the designated storing unit, as a subsequent storing unit;
• if the first storing unit is determined as the designated storing unit, and the total number does not exceeds a threshold number or no storing unit is determined as the subsequent storing unit, feeding a first sheet and then a second sheet from the first storing unit to an image forming section for printing;
• and
• if the first storing unit is determined as the designated storing unit, the total number exceeds the threshold number, and the second storing unit is determined as the subsequent storing unit, feeding a first sheet from the first storing unit to the image forming section and then a second sheet from the second storing unit to the image forming section while the first sheet is being conveyed from the first storing unit.